void BlackoilCo2PVT::computeState(BlackoilCo2PVT::SubState& ss, double zBrine, double zCO2, double pressure) const
{
CompositionalFluidState state;
state.setTemperature(temperature_);
state.setPressure(wPhase, pressure);
state.setPressure(nPhase, pressure);
double massH20 = surfaceDensities_[Oil]*zBrine;
double massCO2 = surfaceDensities_[Gas]*zCO2;
// A priori, assume presence of both phases
brineCo2_.computeEquilibrium(state);
ss.density[wPhase] = state.density(wPhase);
ss.density[nPhase] = state.density(nPhase);
ss.massfrac[wPhase][nComp] = state.massFraction(wPhase, nComp);
ss.massfrac[nPhase][wComp] = state.massFraction(nPhase, wComp);
ss.massfrac[wPhase][wComp] = 1.0 - ss.massfrac[wPhase][nComp];
ss.massfrac[nPhase][nComp] = 1.0 - ss.massfrac[nPhase][wComp];
double detX = ss.massfrac[wPhase][wComp]*ss.massfrac[nPhase][nComp]-ss.massfrac[wPhase][nComp]*ss.massfrac[nPhase][wComp];
ss.phaseVolume[wPhase] = (massH20*ss.massfrac[nPhase][nComp] - massCO2*ss.massfrac[nPhase][wComp])/(ss.density[wPhase]*detX);
ss.phaseVolume[nPhase] = (massCO2*ss.massfrac[wPhase][wComp] - massH20*ss.massfrac[wPhase][nComp])/(ss.density[nPhase]*detX);
// Determine number of phase
if (ss.phaseVolume[wPhase] > 0.0 && ss.phaseVolume[nPhase] > 0.0) { // Both phases
ss.saturation = ss.phaseVolume[wPhase]/(ss.phaseVolume[wPhase]+ss.phaseVolume[nPhase]);
state.setSaturation(wPhase, ss.saturation);
state.setSaturation(nPhase, 1.0 - ss.saturation);
}
else if (ss.phaseVolume[wPhase] <= 0.0) { // Wetting phase only
ss.saturation = 0.0;
// Gas phase:
ss.massfrac[nPhase][nComp] = massCO2/(massCO2+massH20);
ss.massfrac[nPhase][wComp] = 1.0 - ss.massfrac[nPhase][nComp];
double M1 = FluidSystem::molarMass(wComp);
double M2 = FluidSystem::molarMass(nComp);
double avgMolarMass = M1*M2/(M2 + ss.massfrac[nPhase][nComp]*(M1 - M2));
state.setMoleFraction(nPhase, nComp, ss.massfrac[nPhase][nComp]*avgMolarMass/M2);
state.setMoleFraction(nPhase, wComp, ss.massfrac[nPhase][wComp]*avgMolarMass/M1);
ss.density[nPhase] = brineCo2_.phaseDensity(nPhase, state.temperature(nPhase), state.pressure(nPhase), state);
state.setDensity(nPhase, ss.density[nPhase]);
ss.phaseVolume[nPhase] = (massH20+massCO2)/ss.density[nPhase];
state.setSaturation(nPhase, 1.0 - ss.saturation);
// Virtual properties of non-existing liquid phase:
brineCo2_.computeEquilibrium(state, nPhase);
ss.massfrac[wPhase][wComp] = state.massFraction(wPhase, wComp);
ss.massfrac[wPhase][nComp] = state.massFraction(wPhase, nComp);
ss.density[wPhase] = state.density(wPhase);
ss.phaseVolume[wPhase] = 0.0;
state.setSaturation(wPhase, ss.saturation);
}
else if (ss.phaseVolume[nPhase] <= 0.0) { // Non-wetting phase only
ss.saturation = 1.0;
// Liquid phase:
ss.massfrac[wPhase][wComp] = massH20/(massCO2+massH20);
ss.massfrac[wPhase][nComp] = 1.0 - ss.massfrac[wPhase][wComp];
double M1 = FluidSystem::molarMass(wComp);
double M2 = FluidSystem::molarMass(nComp);
double avgMolarMass = M1*M2/(M2 + ss.massfrac[wPhase][nComp]*(M1 - M2));
state.setMoleFraction(wPhase, nComp, ss.massfrac[wPhase][nComp]*avgMolarMass/M2);
state.setMoleFraction(wPhase, wComp, ss.massfrac[wPhase][wComp]*avgMolarMass/M1);
ss.density[wPhase] = brineCo2_.phaseDensity(wPhase, state.temperature(wPhase), state.pressure(wPhase), state);
state.setDensity(wPhase, ss.density[wPhase]);
ss.phaseVolume[wPhase] = (massH20+massCO2)/ss.density[wPhase];
state.setSaturation(wPhase, ss.saturation);
// Virtual properties of non-existing gas phase:
brineCo2_.computeEquilibrium(state, wPhase);
ss.massfrac[nPhase][nComp] = state.massFraction(nPhase, nComp);
ss.massfrac[nPhase][wComp] = state.massFraction(nPhase, wComp);
ss.density[nPhase] = state.density(nPhase);
ss.phaseVolume[nPhase] = 0.0;
state.setSaturation(nPhase, 1.0 - ss.saturation);
}
ss.phaseViscosity[wPhase] = brineCo2_.phaseViscosity(wPhase, temperature_, pressure, state);
ss.phaseViscosity[nPhase] = brineCo2_.phaseViscosity(nPhase, temperature_, pressure, state);
}
